The easyest Pokemon is scizer and the hardest Pokemon is milotic.
You can't really go further then that. The pokemon league contains the toughest trainers in pokemon platinum.
fish with the super rod at the pokemon league
nothing
North of the Pokemon league (Take the seabreak path)
Beat the Pokemon league again and go back to spear pillar and you will see dialga again.
I would use rare candies. Or, train in Victory Road.
In Pokemon league
jynx ..
no
Never mind, I'll ask again... Well the best way in Pokemon platinum if u want a strong Rhydon is to look inside the cave before the Pokemon league.
go to the Pokemon league
no
they are in the Pokemon league.
at the city of the Pokemon league
use the move nuclearbomb
Pokemon league.
The weakest Pokemon at the Pokemon League are at Level 40. The Strongest Pokemon you'll face is at Level 50.